Appelation Controlee wrote:
On Sun, 5 Dec 2010 21:57:12 +0000, Piers Finlayson
wrote:

On 2010-12-05 18:30:17 +0000, Appelation Controlee said:
Not quite what you're asking, but ...

I have opted to DIY my NAS. Rather than buying on off the shelf
(hearing bad things about the reliability of low-end RAID boxes) I have
simply implemented an el cheapo (small, low powered so also cheap to
leave on 24x7) linux box, with two USB attached 1.2 TB hard drives.
One contains all my (music, photo, video, etc) files, and I manually
mirror this hard drive to the other one over night.
I think what you're doing isn't strictly mirroring, it's an internal
backup, possibly file replication. If you want true mirroring, you
could fit an Adaptec SATA RAID card which would mirror the drives so
that if either failed your files would still be available.
If the OS is on mirrored drives, you would suffer no interruption in
the event of a drive failure.
Indeed, I also looked at linux's software RAID support, but decided against
- a hardware solution, as it would have required a larger and more
power hungry PC
- software, because of possible unreliability (and the failure
scenario where the data is unrecoverable.

Software RAID is never more than a substitute for a hardware solution.
well all RAID is software, its just where it lives..;-)